An apparatus includes an XY scanning mechanism, a first transducer configured to transmit a sound wave, a second transducer configured to receive the sound wave, and a tray configured to hold a material. The tray is coupled to the XY scanning mechanism and located beneath the first transducer and the second transducer is located on a bottom side of the tray below the material. The tray is moved in an XY pattern along an X axis and a Y axis in response to an XY scanning mechanism controller mechanically moving the XY scanning mechanism while the first transducer is positioned in a stationary location along a vertical axis perpendicular to the tray. The first transducer transmits sound waves into the material and the second transmitter receives the transmitted sound waves at each XY position.